"Every Conservative in this hall and everyone you represent, we all know individual MPs don't succeed on their own.

"They do so by standing on the shoulders of others... people who volunteered for Mr Reckless, they supported him as a Conservative.

"People who pounded the streets, they supported him as a Conservative. People who donated money from their own pockets, who worked tirelessly for him, they supported him as a Conservative. They did so in good faith.

"Today, your trust has been abused. You have been cheated. Worse, the people of Rochester have been cast aside.

"They voted for a strong Prime Minister who would not duck the hard decisions on our economy, holding our union together or on English votes for English laws.

"As your party chairman I share your deep sense of betrayal and anger.

"We have been let down by somebody who has repeatedly lied to his constituents and to you - who said one thing and then did another.

"Last month, he looked us in the eye and said it is only our Prime Minister who can secure a say for the British people on Europe.

"Last week, he insisted he would be campaigning for an outright Conservative majority.

"Two days ago, he was busy leaving phone messages claiming he was enthusiastic about joining us to campaign... here in Birmingham today.

"He lied and lied and lied again."

Mr Shapps said the Tories would be "campaigning hard" in Mr Reckless's former constituency.

He said: "Let this be a rallying cry - my friends, we are going to campaign hard in Rochester and Strood because the people there deserve an MP who will keep his word because our country needs us now more than ever."

The party chairman insisted the Conservatives' economic policy was "compassionate" while Labour had left businesses "crushed" and unemployment up.

"Our hearts are bigger than that because we understand it's not enough to dream of prosperity, we have to deliver it.

"That's why our economic plan is compassionate, because it is giving us the means to pay for what matters most."

Meanwhile, Mr Shapps said the number of Tory supporters had swelled, with their "Team 2015" group of ground activists up to 25,000 members from 3,000 last year, and record numbers attending conference this year.

He said membership was up and the Tories were raising "hundreds of thousands of pounds" through small online donations of between £5 and £20.

Mr Shapps also revealed that over a million people had signed up to receive party emails.

"There are now more people actively engaged in our grassroots network, than at any time since the famous Primrose League, in the 19th century," he said.

But Labour claimed the Tories were "haemorrhaging members" who were "turning to Ukip".

Trade union Unite claimed Mr Shapps had "inflated" the membership figures by using a wider measure to include "friends" of the party as well as student society members.

Len McCluskey, Unite general secretary, said: "Tory Party membership is in terminal decline and so Shapps is forced to use so-called 'friends' to boost the figures. The Tory's true friends with benefits are the hedge fund managers filling Conservative coffers.

"It seems no coincidence that many Tory polices, from the sell-off of our NHS to tax cuts for fracking, benefit the hedge funds. We should never forget that the Conservatives govern on behalf of the millionaires, not the millions."